Charging and geometric effects on conduction through Anthracene molecular junctions

Abstract

We studied the geometric effects on the charge transfer through the anthracenedithiol (ADT) molecular junction using density functional theory combined with the non-equilibrium Green’s function approach. Two major geometric aspects, bond length and bond angle, were moderated to optimize the electrical conduction. From the results established in this paper, we found that the electrical conduction can be tuned from 0.2 [Formula: see text] to 0.9 [Formula: see text] by varying the Au–S bond length, whereas the moderation of bonding angle assayed a minor change from 0.37 [Formula: see text] to 0.47 [Formula: see text]. We attributed this escalating zero bias conductance to the increasing charge on the terminal sulfur atom of the ADT molecule, which increased the energy of the HOMO orbital towards Fermi level and exhibited a semi-metallic behaviour. Therefore, geometry plays a critical role in deciding the charge transport through the metal/molecule interface.